To extend the range of astronomical telescopes, it is necessary to increase the effective aperture. This implies that larger diameter primary mirrors must be employed. The current state of the art has reached the practical size limit of monolithic mirrors. As a result, segmented primary mirrors that include multiple mirrored petals around a monolithic mirrored center segment have been devised. A space borne telescope employing segmented primary mirrors will require deployment once in orbit. Linear, stable, high stiffness precision latches, with high reliability values, should be used to interlock the metering structure, once the mirror is deployed, to maintain mirror performance. The probability of latch failure during system deployment has to be minimized to ensure mission success. Conventional latching technology, discussed in greater detail below, does not address the need for high stiffness, linearity, and precision in latches that are used for interlocking deployable space telescopes. Furthermore, latch technology, as used in satellite antennae, does not meet optical tolerance requirements. Satellite antennae latches often suffer from repeatability and stability problems that are typically two orders of magnitude below optical system requirements.
Conventional latching mechanisms are categorized either as a retaining type or a mating type latch mechanism. Retaining type latch mechanisms are preset in the latched position and released in their operating state. Examples of this type are illustrated in U.S. Pat. No. 4,682,804 issued Jul. 28, 1987 to William B. Palmer, et al., titled “Releasable Coupling Assembly and U.S. Pat. No. 4,508,296 issued Apr. 2, 1985 to Keith H. Clark, titled “Hemispherical Latching Apparatus.” These retaining latch mechanisms are used to retain payloads during transport, preventing damage due to shock and vibration. Remote release of the latch allows the payload to be removed from the support structure. High reliability and preload are their key performance features; not linearity, stability, or high stiffness precision.
Mating latch mechanisms are illustrated in U.S. Pat. No. 4,431,333 issued Feb. 14, 1984 to Joseph A. Chandler, titled “Apparatus For Releasably Connecting First And Second Objects In Predetermined Space Relationship and U.S. Pat. No. 4,905,938 issued Mar. 6, 1990 to Matthew Braccio et al. These mating latch mechanisms have male couplings that mate with female sockets. Latching occurs after the halves are mated and serve to connect two bodies after contact. These are used to grapple satellites for repair or connection of trusses where only low tolerance alignment is necessary. Again, no consideration is given to linearity, stability, or high stiffness, repeatability and precision of the connection. Consequently, there exists a need for latching mechanisms that are linear, stable, repeatable, and have high stiffness and precision.